1. Field of the Invention
Embodiments of the invention relate to a data storage device. More particularly, embodiments of the invention relate to a hard disk drive with reduced power consumption, a data processing apparatus incorporating the hard disk drive, and a related data input/output (I/O) method.
2. Description of the Related Art
With the advent of the information society, the amount of data individuals need to store and carry has increased dramatically. This need drives a continuing demand for data storage media. Various personal data storage devices have been developed to meet this demand. One example of a data storage device is the hard disk drive (HDD). The HDD is widely used because of its high storage density, high data transmission rate, rapid data access time, and low price. Technically, a HDD is a device that controls the position of a storage disk (i.e., the actual hard disk) during read and write operations directed to data stored on the disk. However, since the HDD and the disk are integrated in a single unit, the term “HDD” is generally understood to include both the hard disk and its drive.
The record-type hard disk contained in the conventional HDD is maintained in an internal vacuum space isolated from the external environment. A Read/Write (R/W) head writes data to and reads data from the disk. A mechanical arm assembly moves the R/W head across the surface of the disk. The conventional disk includes at least one aluminum plate coated with magnetic material. This combination serves as the main data storage medium. The aluminum plate is also called a “platter”. The structure of a conventional HDD is disclosed, for example, in U.S. Pat. No. 4,638,383, the subject matter of which is incorporated herein by reference.
HDDs may be classified into integrated drive electronics (IDE) type HDDs and small computer system interface (SCSI) type HDDs according to their respective interface types. The IDE type HDD includes an installed controller. Accordingly, unlike the SCSI type HDD, the IDE type HDD does not need a separate extension card. The IDE type HDD is also referred to as an advanced technology attachment (ATA). The ATA is a formal interface name defined by the Small Form Factor (SFF) Committee. Recently, a serial-ATA interface defining serial data transmissions has been incorporated into HDD devices.
Contemporary HDDs are mounted not only in desk top computers, but also in mobile devices having various data processing functions, such a notebook computers, MP3 players, cellular phones, personal digital assistants (PDAs), and GPS navigators. Such mobile devices draw power from a finite power source such as a battery. Accordingly, when the stored energy of the battery is expended, the mobile device will not operate. Thus, power consumption for such mobile devices is an ever-present design consideration.
Moderating power consumption by mobile device is a difficult task since overall processing speeds are increasing and the mobile devise are required to perform an ever increasing numbers of tasks. Miniaturization of components has helped reduce power consumption. For example, the development of the system on chip (SOC) technology has reduced total power consumption, but the ratio of total power consumption by the mobile device to power consumption by the constituent HDD has actually increased. Accordingly, further efforts are required to minimize the power consumption of data storage devices, such as HDDs, incorporated in mobile devices.